Due to the fashion trend, the electronic products such as the mobile phone, the portable multi-media player and the personal guiding device, are developed to be smaller, thinner and efficient, so the system integration and wireless for the electronic products will be unavoidable. Accordingly, the manufacturers will not only take more efforts in the industrial design, but also require that the semiconductor chip should have the characteristics of small volume, highly integrated functions, lower power consumption and lower cost. Moreover, the three-dimensional IC will be the next trend, in which the inner link paths are shorter to achieve the faster transmission speed, the smaller noise and the better efficiency between chips. Therefore, many technical manufacturers take efforts to investigate the three-dimensional IC for meeting the market needs.
However, in the semiconductor manufacturing, no matter the CMOS or the MEMS process is used, for the MEMS devices, there is enormous influence of performance caused by residual stress on fabricated microstructure. If the residual stress from the process could be released, the performance, the quality and the reliability of the MEMS devices will be improved.